Projectile control systems and methods
View Patent ↗A method of controlling a projectile includes initiating an execution mode if a roll control authority parameter is outside of a pre-determined operating range for a projectile. The execution mode includes bypassing a guidance command and sending a modified command to execute a coning maneuver to improve control response of the projectile. A projectile control system includes a processor operatively connected to a memory. The memory has instructions recorded thereon that, when read by the processor, cause the processor to execute the method operations described above.
1. A method of controlling a projectile, comprising:
initiating an execution mode if a roll control authority parameter is outside of a pre-determined operating range for a projectile, wherein the execution mode includes bypassing a guidance command, and sending a modified command to execute a coning maneuver to improve control response of the projectile, wherein executing the coning maneuver includes moving at least one control surface of the projectile to change a total angle of attack of the projectile.
2. A method as recited in claim 1 , wherein determining if the roll control authority parameter is outside of the pre-determined operating range includes:
monitoring a speed and a total angle of attack of the projectile; and
initiating a monitoring mode if both the speed and the total angle of attack are outside of respective pre-determined ranges, wherein the monitoring mode includes monitoring of a roll-deflection command and determining if the roll-deflection command is outside of a pre-determined roll-deflection command range, wherein if the roll-deflection command is outside of the pre-determined roll-deflection command range then the roll control authority parameter is outside of the pre-determined operating range.
3. A method as recited in claim 1 , wherein the modified command includes a coning acceleration command.
4. A method as recited in claim 1 , wherein the modified command includes an asymmetric biasing command for providing steering capabilities during the coning maneuver.
5. A method as recited in claim 4 , wherein the asymmetric biasing command includes commanding cyclic movement of at least one control surface of the projectile.
6. A method as recited in claim 1 , further comprising:
exiting the execution mode if a pre-determined exit parameter is met, wherein exiting the execution mode includes cancelling the modified command and returning to the guidance command.
7. A method as recited in claim 6 , further comprising determining if at least one of a total angle of attack and a speed is within respective a pre-determined range, if at least one of the total angle of attack and the speed is within its respective pre-determined range then the pre-determined exit parameter is met.
8. A method as recited in claim 6 , further comprising determining if a terminal performance parameter for the projectile is less than or equal to a pre-determined terminal performance parameter threshold, if the terminal performance parameter is less than or equal to the pre-determined terminal performance parameter threshold then the pre-determined exit parameter is met.
9. A projectile control system, comprising:
a processor operatively connected to a memory, wherein has instructions recorded thereon that, when read by the processor, cause the processor to:
initiate an execution mode if a roll control authority parameter is outside of a pre-determined operating range, wherein the execution mode includes bypassing a guidance command, and sending a modified command to execute a coning maneuver for improved control response of a projectile; and
a projectile operatively connected to the processor, wherein the projectile includes at least one control surface configured to rotate about its respective control surface axis to generate control forces and moments.
10. A projectile control system as recited in claim 9 , wherein to determine if the roll control authority parameter is outside of the pre-determined operating range, the memory has instructions recorded thereon that, when read by the processor, cause the processor to:
monitor a speed and a total angle of attack of the projectile;
initiate a monitoring mode if both the speed and the total angle of attack are outside of respective pre-determined ranges, wherein the monitoring mode includes monitoring of a roll-deflection command and determining if the roll-deflection command is outside of a pre-determined roll-deflection command range, wherein if the roll-deflection command is outside of the pre-determined roll-deflection command range then the roll control authority parameter is outside of the pre-determined operating range.
11. A projectile control system as recited in claim 9 , wherein the memory has instructions recorded thereon that, when read by the processor, cause the processor to:
determine if a pre-determined exit parameter is met; and
exit the execution mode if the pre-determined exit parameter is met, wherein exiting the execution mode includes cancelling the modified command and returning to the guidance command.
12. A projectile control system as recited in claim 11 , wherein to determine if the pre-determined exit parameter is met, the memory has instructions recorded thereon that, when read by the processor, cause the processor to:
determine if at least one of a total angle of attack and/or a speed is within a respective pre-determined range, if at least one of the total angle of attack and the speed is within its respective pre-determined range then the pre-determined exit parameter is met.
13. A projectile control system as recited in claim 11 , wherein to determine if the pre-determined exit parameter is met, the memory has instructions recorded thereon that, when read by the processor, cause the processor to:
determine if a terminal performance parameter for the projectile is less than or equal to a pre-determined terminal performance parameter threshold, if the terminal performance parameter is less than or equal to the pre-determined terminal performance parameter threshold then the pre-determined exit parameter is met.